EP-4741005-A1 - METHOD AND APPARATUS FOR OPTIMIZING A RADIATION TREATMENT PLAN

EP4741005A1EP 4741005 A1EP4741005 A1EP 4741005A1EP-4741005-A1

Abstract

A control circuit 101 identifies 301 a plurality of radiation treatment arclets for a given radiation treatment platform and then identifies 302, for each of the plurality of radiation treatment arclets, a corresponding isocenter location within the patient 104. The foregoing can result in locating the platform isocenter at different locations within the patient during the course of a radiation treatment session for different ones of the arclets. A radiation treatment plan is optimized 303 as a function of the plurality of arclets and their corresponding isocenter locations. By one approach, these teachings will include automatically dividing at least one initial template arc into at least two radiation treatment arclets. By one approach, identifying the corresponding isocenter locations for each of the plurality of radiation treatment arclets can comprise identifying the corresponding isocenter locations to maintain close proximity of a radiation treatment platform collimator to an exterior surface of the patient.

Inventors

KUUSELA, ESA

Assignees

Siemens Healthineers International AG

Dates

Publication Date: 20260513
Application Date: 20251104

Claims (15)

A method for use with a radiation treatment platform having a corresponding platform isocenter and a movement capability of moving a patient with respect to the platform isocenter, the method comprising: by a control circuit: identifying a plurality of radiation treatment arclets for the radiation treatment platform; identifying, for each of the plurality of radiation treatment arclets, a corresponding isocenter location within the patient to locate the platform isocenter at different locations within the patient; optimizing a radiation treatment plan as a function of the plurality of radiation treatment arclets and their corresponding isocenter locations within the patient to provide an optimized radiation treatment plan.
The method of claim 1 wherein identifying the corresponding isocenter locations for each of the plurality of radiation treatment arclets comprises identifying the corresponding isocenter locations to maintain close proximity of a radiation treatment platform collimator to an exterior surface of the patient.
The method of claim 2 wherein the close proximity comprises no more than a predetermined collimator-to-skin distance.
The method of claim 3 wherein identifying the plurality of radiation treatment arclets further comprises determining arclet lengths for at least some of the radiation treatment arclets as a function of the predetermined collimator-to-skin distance.
The method of any one of claims 1 to 4 wherein identifying the plurality of radiation treatment arclets comprises automatically dividing at least one initial template arc into at least two radiation treatment arclets.
The method of any one of claims 1 to 5 wherein identifying the plurality of radiation treatment arclets for the radiation treatment platform comprises identifying at least two radiation treatment arclets that partially, but not wholly, overlap with one another.
An apparatus for use with a radiation treatment platform having a corresponding platform isocenter and a movement capability of moving a patient with respect to the platform isocenter while undergoing radiation treatment by the radiation treatment platform, the apparatus comprising: a control circuit configured to: identify a plurality of radiation treatment arclets for the radiation treatment platform; identify, for each of the plurality of radiation treatment arclets, a corresponding isocenter location within the patient to locate the platform isocenter at different locations within the patient; optimize a radiation treatment plan as a function of the plurality of radiation treatment arclets and their corresponding isocenter locations to provide an optimized radiation treatment plan.
The apparatus of claim 7 wherein the control circuit is configured to identify the corresponding isocenter locations for each of the plurality of radiation treatment arclets by identifying the corresponding isocenter locations to maintain close proximity of a radiation treatment platform collimator to an exterior surface of the patient.
The apparatus of claim 8 wherein the close proximity comprises no more than a predetermined collimator-to-skin distance, and, optionally, wherein the control circuit is further configured to identify the plurality of radiation treatment arclets by determining arclet lengths for at least some of the radiation treatment arclets as a function of the predetermined collimator-to-skin distance.
The apparatus of claim 7, 8 or 9 wherein the control circuit is configured to identify the plurality of radiation treatment arclets by automatically dividing at least one initial template arc into at least two radiation treatment arclets.
The apparatus of any one of claims 7 to 10 wherein the control circuit is configured to identify the plurality of radiation treatment arclets for the radiation treatment platform by identifying at least two radiation treatment arclets that partially, but not wholly, overlap with one another.
The apparatus of any one of claims 7 to 11 wherein the control circuit is further configured to: administer therapeutic radiation to the patient via the radiation treatment platform in a treatment session using the optimized radiation treatment plan.
The apparatus of claim 12 wherein the control circuit is further configured to: automatically adjust, during the treatment session, a distance between a surface of the patient and a part of the radiation treatment platform to avoid a collision therebetween.
The method of any one of claims 1 to 6 or the apparatus of any one of claims 7 to 13 wherein the patient has a head and wherein the exterior surface of the patient comprises an exterior surface of the head.
The method or apparatus of any one of the preceding claims wherein the optimized radiation treatment plan comprises a stereotactic radiosurgery radiation treatment plan.

Description

TECHNICAL FIELD These teachings relate generally to treating a patient's planning target volume with energy pursuant to an energy-based treatment plan and more particularly to optimizing an energy-based treatment plan. BACKGROUND The use of energy to treat medical conditions comprises a known area of prior art endeavor. For example, radiation therapy comprises an important component of many treatment plans for reducing or eliminating unwanted tumors. Unfortunately, applied energy does not inherently discriminate between unwanted material and adjacent tissues, organs, or the like that are desired or even critical to continued survival of the patient. As a result, energy such as radiation is ordinarily applied in a carefully administered manner to at least attempt to restrict the energy to a given target volume. A so-called radiation treatment plan often serves in the foregoing regards. A radiation treatment plan typically comprises specified values for each of a variety of treatment-platform parameters during each of a plurality of sequential fields. Treatment plans for radiation treatment sessions are often automatically generated through a so-called optimization process. As used herein, "optimization" will be understood to refer to improving a candidate treatment plan without necessarily ensuring that the optimized result is, in fact, the singular best solution. Such optimization often includes automatically adjusting one or more physical treatment parameters (often while observing one or more corresponding limits in these regards) and mathematically calculating a likely corresponding treatment result (such as a level of dosing) to identify a given set of treatment parameters that represent a good compromise between the desired therapeutic result and avoidance of undesired collateral effects. In at least some application settings, dose conformality can be a useful measure of the quality of a given radiation treatment plan. Radiation treatment platform physical properties can play a role with respect to dose conformality results. As one example, the penumbra of a beamlet achieved by a multi-leaf collimator can be a limiting factor impacting achievable dose conformality. The width of beamlet penumbra is dependent upon numerous design and implementation details of a multi-leaf collimator, such as leaf tip shape and the elevation of the multi-leaf collimator with respect to the platform's isocenter. The latter can affect penumbra width indirectly by contributing to the distance that the beamlet travels through air before reaching the patient (and ultimately the target region). The applicant has determined that this air-based travel can cause scatter. In addition, this distance can itself cause an increase in the penumbra because the beamlets are often divergent. SUMMARY In one aspect the present invention provides a method as defined in claim 1. The method may be for use with a radiation treatment platform having a corresponding platform isocenter and a movement capability of moving a patient with respect to the platform isocenter while undergoing radiation treatment by the radiation treatment platform. The method may further comprise administering therapeutic radiation to the patient via the radiation treatment platform in a treatment session using the optimized radiation treatment plan, which may optionally include automatically adjusting, during the treatment session, a distance between a surface of the patient and a part of the radiation treatment platform to avoid a collision therebetween. Other optional features are specified in the dependent claims. In another aspect the present invention provides an apparatus as defined in claim 7. Optional features are specified in the dependent claims. BRIEF DESCRIPTION OF DRAWINGS The above needs are at least partially met through provision of the method and apparatus for optimizing a radiation treatment plan described in the following detailed description, particularly when studied in conjunction with the drawings, wherein: FIG. 1 comprises a block diagram as configured in accordance with various embodiments of these teachings;FIG. 2 presents a schematic illustrative example of a single-isocenter field setting for a patient;FIG. 3 comprises a flow diagram as configured in accordance with various embodiments of these teachings;FIG. 4 comprises a schematic representation as configured in accordance with various embodiments of these teachings;FIG. 5 comprises a schematic representation as configured in accordance with various embodiments of these teachings;FIG. 6 comprises a schematic representation as configured in accordance with various embodiments of these teachings; andFIG. 7 comprises a schematic representation as configured in accordance with various embodiments of the invention. Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the